Initiated by a few UCLA students in 2002 as a way of relieving stress during finals week, the Undie Run involves students running through campus, many in their underwear, in the middle of the night at the end of the fall, winter and spring academic quarters. The event has grown substantially and now regularly attracts 8,000 to 10,000 participants, many of whom have no affiliation with UCLA, according to campus and law enforcement officials.

Repeated efforts by administrators, campus police and student leaders to minimize safety risks for students, limit property damage and keep non-affiliated people from joining in have been unsuccessful. The most recent run, in June, was marred by numerous incidents of fighting and vandalism and one robbery, according to campus police, and more than a dozen emergency medical calls were answered by emergency medical services units, most of them alcohol-related.

"What started out as a UCLA student tradition to relieve stress during finals has turned into a free-for-all event attracting large numbers of people who are not affiliated with UCLA and who have demonstrated they have little consideration for the well-being of our students or the surrounding community," said UCLA Associate Vice Chancellor and Dean of Students Robert Naples. "While we regret having to call off the run in the future, we must ensure the safety of our students and the community and also look after UCLA's relationships with our neighbors."

Naples also mentioned the escalating costs associated with damage to university property and police and fire department staffing.